Emission shader on large object is black in Cycles?
As for your... uh... missing(?) light

The default world shader, and an example object;



Your file when first opened;



Disconnecting... whatever you were trying to do there;



Adding a default cube;



Decreasing the strength of your dome's emission... significantly;





As for the point light question

I disconnected the emission (which generates light) and replaced it with a diffuse;



Then I added a point light at a minimally affecting strength (for the size of the dome;



Something a little stronger;



And especially stronger;



Conclusion

I honestly have no idea what your goal is, or if I've answered your question properly. Please let me know.